Steering surface reconstruction of hybrid metal oxides for efficient oxygen evolution reaction in water splitting and zinc-air batteries

Surface reconstruction yields real active species in electrochemical oxygen evolution reaction (OER) conditions; however, rationally regulating reconstruction in a targeted manner for constructing highly active OER electrocatalysts remains a formidable challenge. Here, an electrochemical activation strategy with selective etching was utilized to guide the reconstruction process of a hybrid cobalt-molybdenum oxide (CoMoO4/Co3O4@CC) in a favorable direction to improve the OER performance. Both in-situ Raman and multiple ex-situ characterization tools demonstrate that controlled surface reconstruction can be easily achieved through Mo etching, with the formation of a dynamically stable amorphous-crystalline heterostructure. Theoretical calculations together with experimental results reveal that the synergistic effects between amorphous CoOOH and crystalline Co3O4 are crucial in enhancing the catalytic performance. Consequently, the reconstructed CoMoO4/Co3O4@CC exhibits a low overpotential of 250 mV to achieve a current density of 10 mA cm-2 in 1 M KOH, and more importantly it can be practiced in electrolytic water splitting and rechargeable zinc-air batteries devices, achieving ultra-long stability for over 500 and 1200 h, respectively. This work provides a promising route for the construction of high performance electrocatalysts. (c) 2024 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.